Racial and ethnic differences in the incidence of diabetes have been identified in epidemiological studies. Although recent investigations have associated genetic markers and environmental factors contributing to the diabetes-related phenotypes within populations, the extent to which these factors in fact account for racial/ethnic differences is still unclear. The main objective of this study is to investigate the effect of genetic and environmental parameters on racial/ethnic differences in diabetes-related traits by modeling individual estimates of genetic admixture and environmental measures of energy intake, energy expenditure and socioeconomic status (SES) on measures of fasting insulin, sensitivity to insulin and initial phase of insulin secretion after exposure to glucose. A sample of 120 African-American (AA), 120 European-American (EA) and 120 Hispanic-American (HA) boys and girls of 7-13 years of age will be tested to obtain outcomes of insulin action and response, body composition, energy intake and energy expenditure to questionnaire and SES. The specific aims of this investigation are: (a) To test the role of European genetic admixture on diabetes-related measures of fasting insulin (FI), insulin sensitivity (Si) and insulin response to glucose (AIRg) after adjusted for body composition parameters (2) To investigate how the relationship between the environmental parameters energy intake, energy expenditure and socioeconomic status differ as a function of admixture and diabetes-related measures of fasting insulin (FI), insulin sensitivity (Si) and insulin response to glucose (AIRg), and (3) To test phenotype-genotype associations between ancestry-informative markers (AIMs) and measures of FG, Si and AIRg after adjusted for body composition and environmental parameters in a sample of AA, HA and EA prepubertal children. The proposed investigation will provide meaningful and important insight into the understanding of biological, non-biological and the interaction of both components in racial/ethnic differences in diabetes-related traits. Furthermore, the results of this investigation will serve as a tool for the development of effective preventive strategies to reduce the prevalence of diabetes and its related traits in racial/ethnic populations.